Young boys look on as unidentified armed individuals block the center of Balaklava, near Sevastopol, on March 1, 2014. / Viktor Drachev, AFP/Getty Images

by Anna Arutunyan, Special for USA TODAY

by Anna Arutunyan, Special for USA TODAY

MOSCOW - Russia should not assume it will have an easy time if the nation's forces attempt to impose its will militarily on Ukraine, which the Russian parliament on Saturday said could be occupied by Moscow's troops for "safety" reasons.

"I think this will end badly," said Ilya Ponomaryov, a deputy of the Duma, Russia's lower house of parliament and a member of a party opposed to that of Russian President Vladimir Putin.

"Deploying forces to the Crimea will only galvanize the Ukrainian opposition. And it will only distance Ukraine from Russia," he said.

Russia appeared to have gone ahead with a military takeover of the Crimea Peninsula in East Ukraine, where Russian troops from the Black Sea port of Stevasopol were seen moving through various parts of the region.

On Saturday, the Russian parliament gave Putin permission to use force to protect its interests in Ukraine. Crimea was part of Russia until 1954, when Soviet leader Nikita Khrushchev gave it to Ukraine, which, like Russia, was a part of the Soviet Union.

The newly installed government in Kiev, which ousted the pro-Russia president Viktor Yanukovych a week ago, had no military response to the swift takeover of Crimea by Russian troops in Ukraine aided by pro-Russian Ukrainian groups. Ukraine's acting President Oleksandr Turchynov called it an "invasion" of Ukraine.

Meanwhile, ethnic Russians in East Ukraine are calling for closer integration with Russia and are clashing with pro-Ukrainian groups in some cities.

Alexander Konovalov, head of the Moscow-based Institute of Strategic Assessments, said the moves by Putin do not appear to amount to war yet, "but we're about to get to that point."

Konovalov cited several signals that Moscow was still biding its time. He said Putin's press secretary, Dmitry Peskov, was quoted by Russia's RIA Novosti news service as saying that the actual decision on deploying troops had not yet been issued by the president despite the approval given by the parliament.

Putin may still be weighing the "costs" of invasion, he said.

"If we actually deploy troops, we can expect sanctions within the G8. Russia's economy could suffer a lot of losses, and it's not clear for what.

"And if troops are deployed, Ukrainians will not forgive us for this. And even pro-Russian forces in Ukraine will not agree to give up Ukrainian territory in exchange for Russian support," Konovalov said.

Other opposition party members say Putin has made up his mind.

"(Putin) has declared war on Ukraine and is hoping that the West is busy with other things," said Boris Nemtsov, a former deputy prime minister under President Boris Yeltsin and a co-leader of the PARNAS party.

Konovalov said Putin should be wary of falling into a quagmire, such as when the Soviet Union invaded Afghanistan in 1979.

"We deployed a limited contingent to Afghanistan for a maximum of six months. We stayed there for 10 years," he said. "There will be various consequences."

Ponomaryov also said Putin may still be deciding what to do and may be comparing Ukraine to the Russian invasion of Georgia.

"This was unexpected because during the military campaign in South Ossetia no one asked the Federation Council for permission. It's an attempt (by the Kremlin) to share responsibility," Ponomaryov said.

Other Russian lawmakers insisted the move was a peacekeeping mission, not an invasion.

"We have waited long and patiently hoping that Ukraine could manage on its own. But, unfortunately, it's become clear that without this help and support they cannot manage," Valery Ryazansky, chairman of the Federation Council committee on social welfare, said.

But fears in Russia of a lengthy military conflict swirled on social media.

"Mothers, prepare your sons. They will die. It has been decided. This will take a long time," Russian actor and director Maksim Vitorgan wrote on Twitter.

"That's it. War. This decision will either become (Putin's) 'small, victorious war' but it could also be his 'Afghanistan,' tweeted socialite Ksenia Sobchak, who emerged as an active member of the opposition during Russia's protest wave of 2011-12.